1. Field of the Invention
The present invention relates to a medical device and using method thereof to cure a valve body of a human heart or the like.
2. Description of the Related Art
One of recent problematic heart diseases is such that blood does not flow normally because of incomplete closing of a heart valve body. Examples of such heart diseases include mitral insufficiency in which blood flows back from the left ventricle into the left atrium because of the incomplete closing of a mitral valve and aortic insufficiency in which blood flows back from the aorta into the left ventricle because of incomplete closing of the aortic valve.
These diseases are curable by narrowing an opening portion formed in the heart valve body. Examples of such treatments include a drug treatment and an open-heart operation. In order to cure a heart disease caused by structure only by a drug treatment, it is difficult to adjust the dosage of drugs and there is a problem with fast-acting property. Therefore, these diseases are cured by an open-heart operation. The permanent operation eliminates the risk of relapse though it is invasive. However, inclusively taking into account a risk resulting from the extracorporeal circulation of blood during the operation and the magnitude of invasion resulting from thoracotomy, it is desired to perform the operation through percutaneous catheterization which provides the same effect as that of the open-heart operation.
To meet the desire, the medical device described in U.S. Pat. No. 6,542,766 B2 (see abstract, columns 2 and 3, FIGS. 2A and 16, etc.) has been proposed recently. This medical device is used for treatment as below. A tubular magnetic elongate element is led to a heart using a catheter. A magnetic line is applied to the elongate element from outside so as to orient it in a predetermined direction. Thereafter, an electric current is applied from the magnetic elongate element to an affected area for removal or a drug solution is directly applied to the affected area.
U.S. Pat. No. 6,890,353 B2 (see abstract, etc.) discloses a device which sort of reinforces a mitral valve by implanting a tunnel member in the coronary vein of the heart.
U.S. Pat. No. 6,840,246 B2 (see abstract, etc.) discloses a device which is used to narrow an opening portion by sewing a mitral valve while visually observing the inside of the heart with an endoscope.
In the device disclosed in U.S. Pat. No. 6,542,766 B2, it is difficult to perform the following procedure. A procedure catheter is placed in constantly flowing blood as in the heart and a magnetic line is applied from outside to the procedure catheter to prohibit it from floating. In addition, the treatment using a treatment catheter is limited so that also the treatment has a problem in view of accuracy. In the device disclosed in U.S. Pat. No. 6,890,353 B2, since a foreign object is implanted in the blood vessel, it is probable to impede the smooth flow of the blood. In the device disclosed in U.S. Pat. No. 6,840,246 B2, since the inside of the heart is visually observed with an endoscope, a large amount of normal saline must be allowed to flow to ensure a range of view. However, despite this, it is probably not to perform the accurate visual observation.